A groundbreaking slice of science-fiction - that broke box-office records all over the world - about a monster from another planet loose aboard a spaceship, devouring the crew one by one.

Directed with force if not finesse by Ridley Scott, it has a performance by Sigourney Weaver as Third Officer Ripley that turned her into a screen icon.

A dominant actress with a Jane Fonda voice and a mass of dark curls, it is she who is left to face the alien after it has erupted from the stomach (faint-hearts should get ready to close their eyes at this sequence) of crew member John Hurt, who has been unwise enough to investigate egg-like things on another planet.

The hardware is imposing and the alien itself mostly horrifyingly convincing, although the film's vein of foolishness persists in scenes of characters creeping around alone in darkness in search of the ship's cat when they're all aware that the alien may be waiting with slavering jaws wide open.